Why partitive singular and not plural ? Tänä vuonna 350 000 autoilijaa on saanut ylinopeudesta sakon tai huomautuksen. Why is it 350,000 autolilijaa here and not the plural form since we have a specified quantity ?

Why the use of 'lahjoittaa' here ? "Presidentti sanoo, että rahaa voi lahjoittaa kahteen kohteeseen." Hi I've noticed in Finnish that sometimes in news articles this construction is used - from the context I get that he is supposed to be using the past version of the verb, but the word used is in the singular. So for example from the surrounding context it's clear this sentence means something like "The president says that money can be donated into two charities." but the word used is 'donates' and not 'donated'. Can anyone explain this grammar to me ? Thanks.

Case use here ? Hei. Yks tärkeimmistä asioista, ku muuttaa toiseen maahan tai käy vaan lomalla, on pystyä käydä kaupassa ja ostaa ruokaa ja kaikkea, mitä tarvii. I'm wondering why 'tärkeimmistä asioista' is marked with the -sta case ? I understand when -sta is used to mean 'about' but in this sentence it doesn't really make sense because the person goes on to say 'ku' which sort of makes it not make sense. To me it would make sense if there was no 'ku' because then in English it would mean 'One of the most important things about moving to another country.' Can anyone explain this ? Thanks in advance.

What is being said here ? At 1:49 in this video https://youtu.be/3Yk9H4MxI1c?t=109 I'm hearing 'Miksi että kertonut minulle.' but google says this is wrong. Any ideas ?

Can someone explain the verbs vs the infinitives to me ? How do the '5 infinitives' and the '6 verbs' fit together ? Am i right in thinking the 1st 'infinitive' contains the 6 verbs plus their conjugations for person ? So 'i do', 'i skate', 'i walk' 'you walk' 'he skates' etc ? And you use these for basic sentences ? So if i want to say 'i am walking' would i use this 'infinitive' ? If this is so how do the other 4 'infinitives' fit in ? I think the problem is i've read several very poor grammar sites which explain them in different ways. One says 'The 1st infinitive is the basic form of a verb.' and then when you go to its section on 'infinitives' the '1st infinitive' says: 'Also known as 1. Infinitiivi: translatiivi muoto, this form of a verb answers the question word "why?" or more specifically "in order to do what?". And then gives an example with conjugated verbs. So is it the basic form, or a conjugated form ? I'm so confused.

Why is it jala-STA here ? Kun astut taloon Suomessa, on pakko ottaa kengät jalasta ja jättää ne eteiseen. In Finland, when you come inside, you must take off your shoes and leave them in the foyer/hallway. Why do we use jala-STA if -STA denotes leaving a place ? Thanks.

Elle dit quoi ? https://www.youtube.com/watch?v=6Fw85yRP-WQ à 1:19 - 1:23 elle dit quoi ?

Use of 'y' in this sentence. Nous pratiquons le unschooling, ils avaient clairement besoin d'une soupape de décompression, nous les avons donc laissés tranquille question apprentissages afin de leur permettre d'y redonner du sens et d'y reprendre goût. What do the y's refer to ? Redonner à... ? Reprendre à... ? Thanks in advance.